Optical fiber communications systems, employing fiber optic cables and digital electronics, are widely used in the telecommunication industry to transmit large volumes of data and voice signals over relatively long unrepeatered distances, and virtually noise free. Splice points and drop points for the fiber optic cables are required for most such systems. At a splice point, for example, all of the fibers at one end of a cable are spliced to corresponding fibers of a tandem cable. At a drop point or express splice point, some of the fibers may be spliced to a drop cable, while most of the fibers are passed through the drop point unaltered.
For both splice points and drop points, the optical fibers are exposed from the protective cable jacket to be spliced and secured within a splice closure. The splice closure typically includes a protective housing with either a single end cap through which cables penetrate, that is, a butt-splice; or dual opposing end caps through which respective cables penetrate, that is, an in-line splice.
A typical butt-splice closure, such as the model FOSC 450 enclosure made by Tyco Electronics Corporation, typically includes one or more splices organizers, or splice trays, disposed in stacked arrangement within the protective housing. The trays are pivotally connected at one end to a mounting bracket which, in turn, is connected to the inside face of the closure end cap. The pivotal connection permits individual splice trays to be temporarily moved to a raised position by the insertion of a removable spacer or clip near the pivot point. Accordingly, access is then available to the underlying splice tray, such as to check fiber routing or to remake a defective splice. The cables extending into the housing are secured therein and the penetration point sealed to prevent water from entering the protective housing.
One or more splice holders are also provided in the enclosure and are typically mounted on a splice tray. The splice holder may help to maintain the quality and longevity of optical fiber splices secured within the splice closure. The splice holder retains the individual splices between corresponding optical fibers. A typical splice holder may accommodate four to twelve splices and must adequately secure the splices in the presence of mechanical shocks and vibration. Fiber fusion splice locations are often protected by heat shrinkable protective sleeves. Alternatively, mechanical splices typically employ an assembly to maintain the optical fiber ends in precise alignment. There are a number of popular commercially available mechanical and fusion splice protection devices, most with different exterior dimensions. Splice holder devices typically accommodate only one type of protective sleeve or covering device. Known splice holder device designs use, for example, a series of spaced apart deformable walls of a foam material, pairs of opposing leaf springs, or a lid over the splice holder with a resilient pad positioned within the lid to hold the fiber splices within respective shallow grooves of the underlying splice holder.